Electric secondary clock.



PATENTED FEB. 28, 1905.

I. I. GETTY.

ELECTRIC SECONDARY CLOCK.

APPLICATION FILED MAY 26, 1902.

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| I I I I I I I I I l :IIIIIIIIIIII I PATENTED FEB. 28, 1905.

A PPLIUATION FILED MAY 26, 1902.

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Patented February 28, 1905.

UNTTED STATES PATENT OEEicE.

FRED I. GETTY, OF CHICAGO, ILLINOIS, ASSIGNOR TO AMERICAN CLOCK COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

ELECTRIC SECONDARY CLOCK.

SPECIFICATION forming part of Letters Patent No. 783,?46, dated February 28, 1905.

Application filed May 26, 1902. Serial No. 109,016.

To all whom it may concern:

Be it known that I, FRED I. GETTY, of Chicago, Illinois, have invented certain new and useful Improvements in Electric Secondary Clocks, of which the following is a specification.

This invention relates to improvements in clocks, and refers more specifically to improvements in electric secondary clocks or those which depend for their actuation upon a main or master clock connected up in circuit therewith.

Among the salient improvements of the invention are to provide a mechanism which is not only simple and reliable, but which is entirely or practically noiseless in operation; to provide a mechanism of the character referred to which dispenses very largely with the use of springs and depends for the movement of its parts in one direction upon the direct action of the electromotive force and is controlled to return noiselessly; to provide a construction in which the actuation of the clock is so controlled by the movement of certain of the parts under the influence of gravity that the time-keeping qualities of the clock are unaffected by variations in the power or strength of current which operates the clock; to provide in a mechanism of this character an improved retarding mechanism which insures a gradual movement of the parts to that position in which they are arrested, thereby rendering the movement noiseless; to provide a construction in which the clock mechanism is actuated through the medium of a pallet and pallet-wheel and in which said pallet in itself constitutes the armature, which is directly acted upon by the electromagnet, thereby driving the clock mechanism without the use of intermediate connecting mechanism; to provide a construction which is simple, compact. and adapted to be conveniently supported upon an insulating-plate which in practice forms the dial of the clock, and in general to provide a simple and improved construction of the character referred to.

To these ends the invention consists in the matters hereinafter described, and more particularly pointed out in the appended claims,

and the same will be readily understood from 5 the followingdescription, reference being had to the accompanying drawings, in whicl h Figure 1 is a front elevation of a preferred embodiment of my invention, certain parts of the mechanism being indicated in position be- 5 5 hind the dial by dotted lines. Fig. 2 is a rear elevation of the clock mechanism mounted upon the back side of the dial-plate. 8 is a top plan view of the parts shown in Fig.

2. Fig. 4 is an axial sectional view of the minute-hand shaft and connected parts, including also the hour-hand shaft or sleeve mounted upon the minute-hand arbor. Fig.

5 is an axial sectional view of the dash-pot constituting the retarding device of the mechanism. Fig. 6 is a similarsectional view of a modified form of dash-pot, and Fig. 7 is a top end view or plan of the same with the upper inclosure removed.

Referring to the drawings, 1 designates asa whole a suitable case, which may be of any desired construction, that shown herein being of a usual type provided in its front with a suitable circular opening within which is seated and supported the dial-plate, (designated as 7 5 a whole 2,) said dial-plate being conveniently held in position by means of turn-buttons 3, mounted upon the dial-plate and engaging the margins of the aperture of the casing, within which said plate is seated in the usual manner.

The dial-plate 2 is preferably, and as shown herein, made of insulating n1aterial-such as slate, marble, or the lil e-and made of sufiicient strength to support the clock-movement as a whole, which is directly secured to the 5 inner or rear side thereof, as shown clearly in the drawings. In the preferred embodiment of my invention 1 provide a base-plate or main frame member 4, which constitutes the base member or bar of an electromagnet, 9 and is to this end made of suitable iron and takes the form of a flat metal T-shaped bar, one arm of which is arranged to extend obliquely across the back of the dial-plate and at one side of the centerof the latter, while the other arm extends at right angles to the lirst arm and across the central portion of the dial. Said base-plate is suitably secured rigidly to the dial-plate by means of screws inserted through the dial and into said baseplate, as indicated at 5.

6 and 7 respectively designate the spools ol' the magnet, which are mounted upon the opposite end portions of the bar 5, the core members 8 and 9 thereof being arranged to extend beyond the outer ends of said spools, as best indicated in Fig. 3.

The armature, which is designated as a whole 10, is pivotally mounted between its ends at a point equidistant between the two magnetspools, so that the latter may act upon both ends of said armature simultaneously. To this end the base-bar of the magnet and its COI'G1.)lQCCS are made to serve as a part of the main Frame structure which supports the clock mechanism, and to this end I mount a suitable sLmporting-plate 11, preferably of non magnetic material as, for example, brass upon the outer end of the armaturecores, said su iporting-plate being desirably of T shape in plan view, the two ends of one of its arms being suitably united with the ends of the armature-cores by means of screws 12, while its other arm extends at right angles to the first and across the center of the dial and is supported by means of a standard or frame member 13, with which it is connected by means of a screw 13. The armature 10 is pivotally supported upon an arbor 14, which is journaled to extend between the frameplate 11 and the base frame-plate 4-, said arbor being made rigid with the armature, so as to oscillate with the latter. The length of the armature is slightly less than the distance from center to center of the pole-pieces of the magnet, and said pole-pieces are cut away upon their proximate sides, as indicated in dotted lines at 15, so that the ends of the armature may swing by said pole-pieces without contacting with the latter, and in order to insure a more effective action the ends of the armature are formed upon curves concentric upon its pivotal axis and the cut-away portions of the pole-pieces correspondingly curved. Upon the arbor 14 is rigidly mounted an arm 16, which extends at right angles to said arbor and terminates at its free or outer end opposite the end of a dash-pot (designated as a whole 17) and which is pivotally mounted between bracket-arms 18 and 18, forming a part of the standard or frame member 13. Preferably, and as shown herein, said dash-pot is arranged vertically. Vithin the dash-pot is arranged a piston 19, (see Fig. 5,) with which is connected a piston-stem 20, which extends out through the top closure 21 of the dash-pot and is connected with the arm 16, hereinbetore described. The stem 20 projects through the top closure 21 of the dashpot and is connected to the arm 16 by a pin, which arrangement aflords the necessary relative movement of said parts.

Between the piston 19 and the top closure 21 of the dash-pot is interposed a coiled ex- 'iansion-spring 22, which is so adjusted as to normally force the piston downwardly and return the armature, after actuation in one direction by the energizing of the magnet, to its normal position, or that shown in Fig. 2. The dash-pot is preferably, and as shown in Fig. 5, so constructed that the piston [its loosely in the center, but, nevertheless, close enough to insure a relatively gradual flow of the air past the piston as the latter moves in either direction; but, if preferred, the piston may be made to [it more accurately and a suit able vent-aperture providml therethrough as, for example, as shown in Figs. (3 and T. In practice it is found desirable to have the armature and parts connected therewith practically counterbalanced, so that the action of the spring in the dash-pot is substantially unaffected by gravity, and to this end I provide a counterbalance-weight taking the form o1 an arm 23, in the present instance made integral with the arm 16 and extending in the opposite direction from the arbor. The outer end of said arm is provided with a weight, as indicated at 24:, which is adjusted to practically counterbalance the weight of the piston, pistonstem, and arm 16.

25 designates the main shaft or minutehand arbor of the clock mechanism, which arbor is journaled at one end oi the frame-plate 11 and at its opposite end extends through a suitable bearing in the base-frame member-4, as shown clearly in Fig. 4. In the improved construction shown herein] provide said main shaft 25 with a collar 26, fixed rigidly thereon at a point laterally opposite the armature 10, and upon this collar I mount loosely the pallet-wheel 27, through the medium oi which motion is imparted to said minute-hand shaft. In order to form a yieldingdriving connection between said pallet-wheel and the minute-hand shaft, I mount a spring-washer 28 upon said shaft adjacent to the pallet-wheel, said s in-ing-washer being of dished form and provided with a plurality of radially-extending arms, as indicated clearly in dotted lines in Fig. 2, and in order to hold said washer in yieldingengagement with the pallet-wheel I provide a second collar 29, which is rigidly and adjustably held upon the main shaft by means of a set-screw 30. The friction created by the tension of the dished washer, held be tween the collar 29 and pallet-wheel 27, is suflicient to operate said main shaft properly; but, nevertheless, the latter may be forced around when it is desired to set the hands of the clock without in any wise disarranging the mechanism. In order to actuate the pallet-wheel, I mount a pair of pallet-teeth, as 31 and 32, directly upon the armature 10, one of said pallet-teeth being mounted near the upper end of the armature and the other upon an arm orextension 10, which extends into proximity to the lower side of the pallet-wheel, so

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that said teeth act inalternation as the armature is oscillated. Preferably and as shown herein the teeth of the pallet-wheel and the co '3perating teeth of the pallet are so shaped that an advance movement of the pallet-w heel is caused by the engagement of each pallettooth therewith, this construction being preferred, inasmuch as it insures a more rigid and gradual advance of the hands of the clock. In order that there may be no overthrowing of the pallet-wheel due to inertia, 1 desirably provide a spring brake or friction device in the form of a plate-spring 33, suitably mounted upon the inner face of the frame member 11 and arranged to bear yieldingly against the face of the pallet-wheel,as indicated clearly in Fig. 3.

At a point intermediate the length of the main shaft is provided arigid pinion 34, which is arranged to intermesh with a gear 35, mounted upon a suitable stub-shaft upon the base-plate t, and with the gear 35 is rigidly connected a concentric pinion 36, which in turn intermeshes with a gear 37, rigid with the hour-hand sleeve 38, mounted upon the forward or outer end of the main shaft and extending, together with said main shaft, outwardly through the dial-plate. The train of gears thus described hear such relation to each other that the main or minute-hand shaft rotates twelve times to one revolution of the hour-hand sleeve, as usual. The minute and hour hands 89 and 40, respectively, are mounted upon the ends of the main shaft and sleeve 38 in the usual manner, as indicated clearly in Fig. 4:.

H and L2 designate the conductors through which current is supplied to the electromagnet, said conductors being conveniently made separable and secured to the dial-plate by means of terminal blocks 43, the extensions 41 and 42', which extend from the terminals &3 to" the respective spools of the magnet, being permanently secured to the back of the dial-plate both by connection with said terminals and by means of connecting-buttons 44.

The operation of the mechanism constructed as described may be briefly set forth as follows: It will be understood that the clock is connected in circuit with a main or master clock which serves to send an electrical impulse over the circuit once each minute, and with a clock of this type it is necessary that the impulse be of some duration, inasmuch as the response of the armature is not instantaneous, but retarded, as will appear. The electromagnet being energized, the armature is caused to approach a position in alinement with the pole-pieces of the magnet, but is compelled to approach its closed position gradually by the action of the dash-pot 17, and in this connection it is to be noted that the armature is arrested by the engagement of its lower pallet-tooth with the pallet-wheel. As said tooth passes into engagement with the pallet-wheel the latter is stepped forward a part of the distance of one tooth, thereby actuating the connected train of clock mechanism. As soon as the magnet is deenergized by the interruption of the circuit of the master-clock the armature under the action of the coil-spring Q2 of the dash-pot is returned gradually to its normal position, and during such movement the upper pallet-tooth engages the pallet-wheel and forces the latter forward the remainder of the distance of one tooth. Owing to the inclined shape of the coopcrat ing pallet-teeth, the movement imparted to the pallet-wheel is relatively slow, and this gradual movement is insured by the action of the dash-pot or retarding device.

It will be seen from the foregoing that the mechanism if properly constructed will be practically noiseless, since the only engagement of parts which could produce noise is 'the engagement of the pallet-teeth with the pallet-wheel, and this engagement is so gradual as to not produce a perceptible noise.

If preferred, I may so modify the heroinabove-described mechanism as to permit the parts to return by gravity to their normal position, and in such event I omit the expansion-spring of the dash-pot, as shown in Figs. 6 and 7 and increase the weight of the piston sufiiciently to cause it to return of its own weight and actuate the clock-train. Such a construction has the advantage of dispensing with the spring 22, but has the disadvantage of producing a slight noise when the pallettooth passes into engagement with the palletwheel and arrests the return movement of the armature.

It will be understood from the foregoing description that the details of construction may be modified without departing from the spirit of the invention, and 1 do not, therefore, limit myself to such details except to such extent as they are made the subject of specific claims.

I claim as my invention- 1. In an electric clock the combination of a base-plate and a supporting-plate arranged in parallel relation with each other, the base-plate constituting the base member of an electromagnet, magnet-spools interposed between and secured to said members, an armature pivot-- ally mounted to oscillate between the ends of the cores of the magnet, pallet-tooth projections formed or mounted directly upon said armature, bevel-shaped pallet-teeth upon said projections, a pallet-wheel mounted between said projections, said pallet-teeth alternately and by a gradual contact engaging the teeth of said pallet-wheel and giving an advance movement thereto, said armature projections, teeth and pallet-wheel all being adjacent to each other and lying in parallel planes, and a clock-movement proper mounted between said base-plate and said supporting-plate, substantially as shown and described.

2. In an electric clock the combination of a base-plate and a parallel supporting-plate, both approximately T-shaped in outline and arranged in register with each other, the baseplate constituting the base member of an electromagnet, the magnet-spools interposed between and pivotally mounted to oscillate between the ends of the cores of the magnet, projections upon said armature, bevel-shaped pallet-teeth upon said projections, a palletwheel mounted between said projections, said pallet-teeth alternately and by a gradual contact engaging the teeth of said pallet-wheel 

